Multi-purpose acid compositions

ABSTRACT

The invention relates to solutions containing acidic compositions that have a pH of less than 1, are non-caustic to human tissue and are safe for human ingestion. These compositions may be used as the sole or major component of solutions such as cleansers, pharmaceuticals, food preservatives and disinfectants. The acidic compositions may be used in medical, industrial, military and household applications. The invention also relates methods of administering and using the acidic compositions of the invention.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of application Ser. No. 10/118,360,filed Apr. 9, 2002, which is a divisional of application Ser. No.09/487,174, filed Jan. 19, 2000 (now U.S. Pat. No. 6,375,976), whichclaims the benefit of U.S. provisional application No. 60/116,628, filedJan. 19, 1999. All referenced applications are incorporated herein intheir entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to acid compositions that are useful infood, medical, commercial and military industries and also as generalhousehold products. These compositions have a low pH, are relativelynon-corrosive to metals, do not harm skin and are safe for use in foodand beverages. The invention also relates to formulations that containthese acid compositions and to methods for using such formulations.

2. Description of the Background

Low pH compositions and solutions containing acidic compositions areused for various industrial and general household purposes, such ascleaning and sterilizing surfaces and articles of manufacture. Examplesinclude well-known household cleansers and disinfectants, industrialmicrochip production and cleaning agents, and anti-microbials. To workboth effectively and efficiently, these solutions typically containstrong acids or organic solvents, which present health concerns to theuser, may be corrosive to the substances they are designed to clean(e.g. metals) and pose an ecological hazard with respect to disposal.

There have been a number of efforts aimed at developing less corrosiveand less toxic acidic products. For example, U.S. Pat. No. 4,459,202 isdirected to an acidic composition for recovering bituminous productsfrom tar sands. Two strong and two weak acids are combined to form anacidic solvent that can be used to remove and recover the bituminousproducts. The composition is described as being non-corrosive and lesshazardous to handle than other strongly acidic solutions.

The molecular effect of combining first and second strong acids with thethird and fourth weaker acids forces the weaker acids to act asconjugate bases for the strong acids and to accept hydrogen ions(actually hydronium ions in aqueous solution) from the strong acids. Theresulting acidic solution has a very low pH value, and a large amount offree hydrogen ions. However, the ability of this strong acidiccomposition to effectively function as a solvent may sometimes requiremore acid than would be considered safe or non-hazardous to humantissue. Moreover, there is no suggestion that this composition can beused in other applications, such as in products which come into contactwith food. In fact, the composition cannot be used in connection withfood and drink, as one or more of its components are not listed on theU.S. Food and Drug Administration list of substances consideredgenerally recognized as safe (GRAS).

Various formulations using multiple acid compositions are disclosed inU.S. Pat. Nos. 4,675,120, 4,970,014, 4,970,015 and 5,019,288. Each ofthese compositions is described as either useful for well-acidizing,tertiary oil recovery, removing rust from metal, cleaning aluminum,radiator cleaning, boiler and heat exchanger cleaning, or coppercleaning. These compositions are described as generally non-corrosive tometal and relatively inert when contacted with human tissue. Inaddition, U.S. Pat. No. 4,483,887 describes a multiple acid solutionuseful for metal plating. U.S. Pat. No. 4,477,364 describes a multipleacid solution useful for cleaning glassware.

Although these acid-based solutions may be effective for the variousdescribed purposes, a major drawback is that certain formulations cancause skin irritation. For example, studies conducted using a topicalskin disinfectant containing the core composition of U.S. Pat. No.4,459,202 found that the product caused reddening of the skin and aburning sensation. Similar reddening of the skin and burning sensationresulted with a cleaning solution containing the core acid compositionof U.S. Pat. No. 4,459,202. As such, these acid compositions cannot besafely used in products where skin contact is a possibility. Inaddition, such compositions cannot be used in products associated withfoods or beverages. Further, many of these compositions require amultiplicity of components, leading to increased production costs.

U.S. Pat. No. 5,512,200 is directed to a multiple acid compositiondescribed as non-irritating to the skin and useful as a component ofproducts such as cleansers, cosmetics and pharmaceutical agents.However, at least one of the components is not considered GRAS. Thus,despite the relatively inert nature of this composition, it cannot beused in foods or drinks, or in products associated with foods or drinks.

There is therefore a need for acid compositions comprising a minimumnumber of component acids, all of which components are approved by theFood and Drug Administration as GRAS, with broad utility for cleaning,sterilizing and anti-microbial uses that are effective, non-toxic andsafe for use with food and food-related products.

SUMMARY OF THE INVENTION

The invention overcomes the problems and disadvantages associated withcurrent strategies and designs and provides novel low pH compositionsuseful in medical, military, industrial and household settings. Theseacid compositions can be used as the sole or core component of solutionsincluding cleansers, anti-microbial agents, disinfectants,decontaminants, pharmaceuticals, cosmetics, anti-odor agents andsterilants.

The low pH compositions of the present invention are safe for use aseither the sole or major component of solutions including, but notlimited to, disinfectants, cleansers, sterilizers, cosmetics, andpharmaceutical agents, and can be used in industrial, medical, militaryand general household settings. The compositions of the presentinvention are safe not only for use in products which contact humanskin, but also for use in ingestible products.

One embodiment of the invention is directed to an acid solution forinhibiting microbial growth comprising an aqueous acidic corecomposition which makes up 50% to 100% of the solution. The acidic corecomposition consists of acids that are safe for use in food and drinkproducts and food- and drink-associated products (i.e. GRAS substances).The acidic core composition may be prepared by admixing from about zeroto about 25%, by volume, of a first acid, preferably between about 0.1%to about 15%, and more preferably between about 0.5% and about 10%, withbetween about 1% and about 25%, by volume, preferably between about 2%and about 15%, and more preferably between about 5% and about 10%, of asecond acid to produce a first acidic composition.

The first acid is an inorganic acid that dissociates nearly tocompletion in water. The second acid is an inorganic acid less strongthan the first, having a dissociation constant of less than about 10⁻¹.A second acidic composition is formed by mixing from about 0.5% to about20%, by weight, preferably from about 2% to about 15%, and morepreferably from about 6% to 10%, of an organic hydroxy acid with water.The organic hydroxy acid has a greater chelating capability (generallyat least twice) or iron binding efficiency as one or the other of thefirst and second inorganic acids. Acids with at least twice the ionbinding efficiency of the inorganic acids include, for example, ascorbicacid, citric acid, lactic acid, malic acid and tartaric acid.

The two acidic compositions or solutions are then mixed to produce anacid core composition that inhibits microbial growth and is safe for usein food products. This composition preferably has a pH of less than one,yet will not adversely react with human tissue.

In a preferred embodiment, the first acid is hydrochloric acid, thesecond acid is phosphoric acid, and the organic hydroxy acid is citricacid. Generally, the quantities of the first acid will balance thequantity of the second acid such that less of the first acid will berequired when using more of the second acid. A maximum quantity of thesecond acid is that amount which will require the addition of no firstacid when admixed with the organic hydroxy acid to produce the low pHcomposition of the invention.

The acid composition of the present invention maintains the low pH andnon-toxic qualities of conventional acidic compositions, yet, unlikethese compositions, is safe to use in food and food-associated products,such as paper for packaging and wrapping food, food containers, foodpreserving agents and ingestible products.

In contrast, acids used in a number of conventional products, such as,for example, hydrofluoric, sulfuric, nitric, chloric, perchloric,chlorous, hydrofluoric, hydrosulfuric, fumaric, oxalic, phthalic,tartaric, acetic, acrylic, benzoic and carbonic acid, are not generallyrecognized as safe, and none are federally approved for use iningestible products or products contacting ingestible products. Further,as many of the conventional acid-based solutions are toxic, disposal andhandling of such compositions require special measures not necessarywhen utilizing compositions of the invention.

Another embodiment of the invention is directed to a pharmaceuticalcompound comprising a three acid composition, the three acid compositioncomprising: a first acid, wherein the first acid is an inorganic acidthat dissociates nearly to completion in water; a second acid, whereinthe second acid is an inorganic acid less strong than the firstinorganic acid and has a dissociation constant of less than about 10⁻¹;a third acid, wherein the third acid is an organic hydroxy acid which isweaker than the first and second acids, has a greater chelatingcapacity, generally at least twice, of either first or second acid, andhas a dissociation constant of from about 10⁻¹ to 10⁻⁵; and apharmaceutical agent. Preferably, the three acids are GRAS acids.

Another embodiment of the invention is directed to a composition forprocessing food items comprising a three acid preservative consistingof: first inorganic GRAS acid that dissociates nearly to completion inwater; a second inorganic GRAS acid less strong than the first acid andhaving a dissociation constant of less than about 10⁻¹; and a third GRASacid, the third GRAS acid being an organic hydroxy acid that has atleast twice the chelating efficiency as either of the inorganic acids.Preferably, the organic hydroxy acid is weaker than the first and secondacids and has a dissociation constant of from about 10⁻¹ to 10⁻⁵. Anespecially preferred food processing composition comprises hydrochloric,phosphoric and citric acids.

Another embodiment of the invention is directed to a method ofpreserving food comprising the addition of a three acid preservativecomposition to a food substance. The three acid preservative compositioncomprises: a first GRAS acid which is an inorganic acid that dissociatesnearly to completion in water; a second GRAS acid, the second GRAS acidbeing an inorganic acid less strong than the first GRAS acid and havinga dissociation constant of less than about 10⁻¹; and a third GRAS acid,the third GRAS acid being an organic hydroxy acid weaker than the firstand second GRAS acids, with chelating capability at least twice as greatas either or both of the first and second GRAS acids and a dissociationconstant from about 10⁻¹ to 10⁻⁵.

Another embodiment of the invention is directed to a method fordecontaminating surfaces comprising contacting the surface with an acidcomposition of the invention comprising: a first GRAS acid, wherein thefirst GRAS acid is an inorganic acid that dissociates nearly tocompletion in water; a second GRAS acid, wherein the second GRAS acid isan inorganic acid less strong than the first inorganic acid and has adissociation constant of less than about 10⁻¹; and a third GRAS acid,wherein the third GRAS acid is an organic hydroxy acid weaker than thefirst and second GRAS acids, but being at least twice as efficient aseither or both of the first and second inorganic acids in its chelatingability and having a dissociation constant of from about 10⁻¹ to 10⁻⁵.

Another embodiment of the invention is directed to a method for treatinga surface to inhibit microbial growth on the surface comprisingcontacting the surface with a three acid composition according to theinvention.

Other objects and advantages of the invention are set forth in part inthe description which follows, and in part, will be obvious from thisdescription, or may be learned from practice of the invention.

DESCRIPTION OF THE INVENTION

As embodied and broadly described herein, the present invention isdirected to low pH acidic compositions that are generally recognized assafe. Compositions according to the invention are safe for use in food,beverage, or other ingestible products and do not irritate the skin. Thepresent invention is useful in industrial, medical, military, andhousehold applications. Medical applications include use on humans andanimals. The invention also relates to formulations containing theacidic compositions of the invention, applications of thesecompositions, and to methods of making and using these compositions.

Many of the acidic compositions currently used in industrial, medical,military and household settings present health hazards to the user andare corrosive with prolonged exposure to the surfaces they contact. Useof these compositions often requires special protective clothing andapplication methods. Additionally, disposal of these toxic products in amanner which ensures the safety of the environment and personnel iscostly and time consuming. Although some conventional compositions areless caustic to skin and, overall, less hazardous to the user thanothers, they are, nonetheless, not safe for use in food and beverages orin other ingestible products.

An acid composition that can be safely handled and applied directly tohuman skin has been discovered which, unlike conventional acid-basedcompositions, uses a minimum number of ingredients, all of which arefederally approved for use in food and drink products and food- anddrink-associated products. Compositions of the invention are alsoapplicable for industrial, military and general household uses. Inaddition to being suitable for use on and by humans, the presentinvention is also appropriate for animals. The compositions of theinvention are effective and may be used over a wide range oftemperatures, including room temperature. Thus, the present inventionprovides an advantage over sterilants which require a power source orenergy, such as heat (autoclaving). Moreover, acid compositions of theinvention have a shelf life of one year or greater when stored atambient temperature.

One embodiment of the invention is directed to a low pH acid compositioncomprised only of GRAS substances. GRAS substances are those substanceswhich are approved for use in food, beverages and other ingestibleproducts, and in products which contact these materials. Specifically,these substances, listed at 21 C.F.R. Part 182 and Part 184, arerecognized by the FDA as safe for use in foods, beverages and ingestibleproducts, and in products associated with foods and beverages. Suchsubstances are generally considered non-carcinogenic. As such, thecompositions of the invention are safe to use in association with foodand drinks and other ingestible products.

In a preferred embodiment, three acids are used. The first acid ishydrochloric acid, the second acid is phosphoric acid, and the thirdacid is citric acid. In this embodiment, the first acid of thecomposition, hydrochloric acid, comprises between about zero to about 25volume percent of the final composition, preferably between about 0.1 to20 volume percent, and more preferably between about 5 to about 10volume percent of the final composition. Hydrochloric acid is a stronginorganic acid which dissociates nearly to completion in water. Someparticularity useful acid compositions of the invention contain about0.1%, 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 14%, 15%, 18%,20%, 21%, 22% and 24% of the first acid.

The second acid of the composition, phosphoric acid, is also aninorganic acid but is less strong than hydrochloric acid. Phosphoricacid thus functions as a conjugate base and accepts hydrogen ions(actually hydronium ions in aqueous solutions) from the strongerhydrochloric acid. The phosphoric acid comprises between about 0.1 toabout 20 volume percent of the final composition and preferably betweenabout 1 to 15 volume percent, and more preferably between about 5 toabout 10 volume percent of the final composition. Some particularityuseful acid compositions of the invention contain about 0.5%, 1%, 2%,3%, 4%, 5%, 6%, 8%, 10%, 12%, 13%, 14%, 15%, 16% and 18% of the secondacid.

The third acid is an organic acid (e.g. citric acid) belonging to thegroup of hydroxy carboxylic acids and is a weak acid relative tohydrochloric and phosphoric acids. Specifically, citric acid is a6-carbon, tricarboxylic acid. Citric acid preferably comprises betweenabout 1 to about 15 weight percent, preferably between about 5 to about10 weight percent and more preferably between about 6 to about 9 weightpercent of the final composition. Some particularity useful acidcompositions of the invention contain about 0.5%, 1%, 2%, 3%, 4%, 5%,6%, 8%, 10%, 12%, 13%, 14%, 15%, 16%, 17% and 18%, by weight, of theorganic hydroxy acid.

A preferred embodiment of the improved aqueous acidic composition of theinvention may be prepared by a process involving the following steps:

(1) mixing at room temperature from about 5 to about 10 (most preferably6.60) volume percent hydrochloric acid (HCl being principallyresponsible for the resulting pH) with from about 1 to about 5 (mostpreferably 4.49) volume percent phosphoric acid in a first container fora period of time sufficient to produce a homogenous mixture;

(2) mixing at room temperature in a second container from about 5 toabout 10 (most preferably 7.50) weight percent citric acid with fromabout 85 to about 90 percent water for a period of time sufficient toresult in thorough mixing; and

(3) admixing at room temperature the hydrochloric/phosphoric acidmixture held in the first container into the citric acid/water mixtureof the second container until a homogenous composition results.

The acid aqueous composition of the present invention is basicallycolorless (high concentrations of HCl produce a greenish to yellowishcolor), has a pH of less than one, will not harm human tissue, andcontains only substances approved by the Food and Drug Administration tobe GRAS substances. Thus, the resulting aqueous acidic composition issafe for use in food, drink, and other ingestible products. Thecomposition of the present invention is also much less corrosive tometals than acid compositions at a similar pH. Delicate instruments suchas, for example, dental instruments, surgical and other medicalinstruments, and computer parts, can be effectively cleaned using anacid composition of the invention without harming the delicatecomponents or parts of the instrument or causing undue wear.

The acid composition of the present invention may be used alone or asthe base, core or active component in the formulation of othersolutions. Additional ingredients, if desired, may be added to the threeacid composition depending on its intended purpose or application.Substances may be added to the core acid composition, for example, toincrease the retention time of the product on the skin, to give anappealing color or scent to the composition, to produce a specifictexture, or to increase the specificity of application of thecomposition. Additives such as anesthetic agents (e.g. lidocaine), pHindicator dyes and other dyes and contrast agents can be added dependingon the application.

The compositions of the present invention are suitable for use in aplurality of food industry, household, military, medical and industrialsettings. Just a few potential uses of the compositions of the presentinvention include: cleaning and disinfecting surfaces, instruments,foods and equipment; antimicrobial component for hygiene products,preparation of skin surface for injections, topical ointments, creams,gels, inhalants (generally used at concentrations of 5%, 4%, 3%, 2%, 1%or less), mouth and eye washes, activation of immune-response (e.g.stimulates non-specific immunity); anti-odorant; cleaning anddisinfecting food items and food processing (e.g. removes coffee and teastains), packaging and storage materials; pH- and/or microbial-controlagent (swimming pools); a detoxifying/decontaminating composition forclean up of chemical spills or hazardous materials (HazMat)(decontamination showers) (eliminates toxic cloud/fumes from acid spillsat various mixtures such as 10:90, 25:75, 60:40, 50:50, 40:60, 75:25 and90:10 mix depending on the acid); manufacture of food processing,packaging and transportation items; detoxifying composition forindustrial settings (i.e. paper mills and other industrial plants, andlaboratories may use HCl and/or sulfuric acids; can treat HCl burns withinvention); industrial showers (acid showers); manufacture ofacid-containing solutions and products (i.e. batteries containing“battery acid” such as sulfuric acid; by mixing with invention, lesstoxic and less fuming); cleaning battery posts; sterilization orpurification of water supply; non-toxic embalming agent;detoxification/deactivation of chemical and biological warfare agents;and cleaning air ducts.

Specific veterinary, dental and medical applications include woundcleaning and disinfecting, disinfecting and sterilizing floors, surfacesand instruments (dialysis apparatus), topical treatment of skininfection, treatment of topical irritants (poison ivy and poison oak),sterilization of indwelling devices (e.g. catheters, IV drips); anti-STDapplications (i.e. suppositories, creams, gels, condoms, mouthwashes,douches); treatment of burns, sunburns, ear infections, insect bites,jellyfish stings, anti-coagulant, treatment of medical waste, andanti-fungal agents (e.g. anti-jock itch treatment, prevention ortreatment of athlete's foot).

The invention can also be used as an anti-odorant to neutralizeammonia-based odors/wastes, biological specimens, chemical toilets,animal bedding and diapers. It may be used as an underarm deodorant. Inconnection with food, it may be used to spray produce, clean anddisinfect food transport containers and fluid lines or any surfacecoming in contact with food and food serving materials. It may beapplied to seafood as a deodorizer and be used to spray live animals orto spray meat before wrapping, etc. As an antibacterial, anti-fungal andsporicide, it may be used, for example, as an acidifier in home canning.

With respect to military applications, the invention may be used todecontaminate chemical warfare agents on personnel and surfaces, andgiven its broad spectrum of activity, is ideal for incorporation intobandages and sponges. The invention may be incorporated into a missileor other delivery device as a countermeasure to deactivate chemicalwarfare or biological agents (e.g. protein toxins such as anthrax,botulism and E. Coli) delivered by or contained in another weaponsystem. It may be delivered to a broad contaminated area through the useof a fog/smoke generating device, crop-dusting or firefighting aircraft.

Applications also include use as a non-toxic embalming agent, anti-scalebuild-up and treatment of water supplies, electrolyte sports drink,treatment of personal items such as toothbrushes or hairbrushes, safetyshowers for certain industries using acids, acid spill or acid cloudclean up. It may be used as a silver or chrome polish, to removeoxidation build-up on heat exchangers, pipes and water heaters, todescale sinks, water storage tanks, showers and the like to removebarnacles, or to clean concrete. It may be used as a fixative for fabricdyes (pH indicator dyes bonded to cotton fabrics—dye retained aftermachine laundering; also may be used in wearable pH indicator garmentswhich are acid or base sensitive). It may be used as a preservative forfoods, biological specimens, forensic specimens and biological specimensand lumber. It may be used as a buffer for noxious solutions or toinhibit the corrosive properties of bleaching solutions. Furtherapplications include etching aluminum or porcelain, and use as ananti-freeze or water purifier. Because the invention is compatible withpH indicator dyes, solution efficacy can be visually determined. Also,solutions have the potential for repeated re-use (i.e. can be recycled).

Another embodiment of the invention is directed to a pharmaceuticalagent or compound containing the acid composition of the presentinvention. As will be clear to those of skill in the art, varioussubstances may be added to the aqueous acidic composition of thisinvention as desired to produce a pharmaceutical agent. The terms“pharmaceutical agent” or “pharmaceutical compound” as used herein areused in their broadest possible sense and include, but are not limitedto, medications and all types of therapeutic agents, whether takenorally, parenterally, topically, or by any other route. Usefulsubstances which may be added to produce a pharmaceutical agent include,but are not limited to, anesthetic agents, alcohols, creams, gels, aloevera, vitamin E, PFP (polyfluorenated perfluorate, e.g. TEFLON,FOMBLIN), moisturizers, emollients, surfactants, humectants, scents,colorants, glycerin, propylene glycol, emulsifiers, wetting agents, pHindicator dyes, medically-relevant dyes, contrasting agents, andcarriers known in the art. Uses of the pharmaceutical agents orcompounds formulated with the three acid composition include, but arenot limited to, deodorants, mouthwashes, topical antimicrobial ointmentfor wounds, and compositions for the treatment of a wide variety ofmaladies, including dry skin, wrinkles, acne, age spots, sunburn,infections (viral, bacterial and fungal), insect bites and rashes. Thepharmaceutical agent may be appropriate for use on mucous membranes,including the mouth and eyes. The pharmaceutical agent or compound canbe brought into contact with the surface to be treated either directlyor via applicators, including, but not limited to, sponges, towelettesand pads.

Another embodiment of the invention is directed to decontaminationagents containing acid compositions of the invention. These agents areparticularly useful in military and industrial applications. Thesedecontamination agents provide protection from, or directly inactivate,a variety of toxic chemical agents, such as those used in chemicalwarfare, farming, and lawn care. Such toxic chemicals include, but arenot limited to, insecticides, pesticides, mustards, nerve agents,blister agents, cholinesterases and cholinesterase inhibitors ingeneral. Additionally, decontamination agents according to the inventionare effective in the inactivation of biologically toxic molecules suchas those used in warfare. Biologically toxic molecules include, but arenot limited to, aflatoxins, biological toxins, exotoxins, endotoxins,poisons, phytotoxins, insect and animal venoms and mycotoxins. Becauseof the non-caustic nature of the acid compositions of the presentinvention, these decontamination agents may be applied either directlyto the skin, or may be applied to clothing or other materials that comein contact with skin. Thus, the present invention is suitable for use byfirst-responders in decontaminating physical surfaces, treating woundsin humans or animals, and/or deactivating chemical agents includingnerve agents.

In a preferred decontamination compound, a three acid composition ismade into a reactive topical skin protectant which may be mixed with aperfluorinted polyether grease vehicle, a water-based vehicle, or othersuitable vehicle. Use of alternative vehicles allows for flexibility inapplication of the topical protectant. The resultingdecontamination/protection barrier is active over a broad temperaturerange of from about −10° C. to about 50° C., and is stable for one yearor longer when stored at ambient temperatures.

Another preferred embodiment is directed to a decontamination compoundin which the acid composition is incorporated into towelettes orsponges. The use of these towelettes or sponges allows for safe andrapid detoxification of organophosphate compounds (e.g. nerve agents),as well as viruses, bacteria and toxic molecules. The towelettes orsponges are easily carried by personnel and used by first-responders indecontamination steps. The towelettes or sponges are active over a broadtemperature range of from about −10° C. to about 50° C., and have ashelf life of one year or longer.

Another embodiment of the invention is directed to cleansing agentscontaining the acid composition. These cleansing agents include, but arenot limited to, glass cleansers, metal cleansers, household cleaningsolutions (kitchen and bathroom), and solutions to remove oxidationbuild-up from pipes and water heaters and heat exchangers. In this useof the invention, detergents, soaps, scents or strong acids may be addedas needed to the acid composition.

In a preferred cleansing agent, hydrochloric acid is added to the acidcomposition in ratios ranging from about 0.1 parts to 30 parts (byvolume) of the acid composition to produce a solution suitable for useas a metal cleaner. Addition of more hydrochloric acid reduces the timerequired for cleaning; however, this may result in a product whichirritates skin.

Another embodiment of the invention is directed to the use of theinvention as an antimicrobial agent such as a disinfectant or sterilant.These disinfectants and sterilants may be used, for example, tosterilize drinking water, disinfect surfaces, treat wounds, sterilizehair care and manicure equipment, sterilize dental equipment, sterilizehospital clean rooms, sterilize tissue culture hoods in laboratories,and sterilize biological waste. The three acid composition of thepresent invention may also be used in cleaning or sterilizing containersused in the transportation and storage of food and drink, such as trucktanks, vats and fluid lines.

Substances including, but not limited to, perfumes, aerosols, dyes,alcohols, reducing agents, anesthetic agents, oxidizing agents, amines,amides, surfactants, creams, gels and other acids may be added to thecompositions of the present invention as needed for a particularapplication.

Another embodiment of the invention is directed to a composition forprocessing food comprising a three acid preservative consisting of afirst inorganic GRAS acid that dissociates nearly to completion inwater, a second inorganic GRAS acid having a dissociation constant ofless than about 10⁻¹, and a third GRAS acid being an organic acid weakerthan the first and second acids, and having a dissociation constant offrom about 10⁻¹ to 10⁻⁵. An especially preferred food processingcomposition comprises hydrochloric, phosphoric and citric acids.

Food processing compositions of the present invention may be suitablefor decontaminating food items, such as, for example, meats, fruits orvegetables. In a preferred embodiment, the composition is applied tofruits and/or vegetables to remove or effectively destroy residualpesticides. The food processing composition may also be suitable for useas a de-odorize for seafood and as an antimicrobial treatment for meatproducts.

Another embodiment of the invention is directed to a method ofpreserving food comprising the addition of an acid preservativecomposition to a food substance, the acid preservative compositioncontaining a first GRAS acid, the first acid being an inorganic acidthat dissociates nearly to completion in water; a second GRAS acid, thesecond acid being an inorganic acid less strong than the first inorganicacid and having a dissociation constant of less than about 10⁻¹; and athird GRAS acid, the third acid being an organic acid weaker than thefirst and second acids, the third acid having a dissociation constant offrom about 10⁻¹ to 10⁻⁵.

The above formulations and applications are intended to merelyillustrate the wide range of utility of the compositions describedherein and are not intended to be an exhaustive listing of all possibleformulations and uses of compositions according to the invention. Also,as the list of substances approved by the U.S. Food and DrugAdministration to be Generally Regarded As Safe (GRAS) is revised, sowill be the acids available for use in the compositions of theinvention. As will be clear to those of skill in the art, compositionsthat are safe for human ingestion or contact are likewise safe foringestion or contact by other animals.

The following examples are offered to illustrate embodiments of thepresent invention, but should not be viewed as limiting the scope of theinvention.

EXAMPLES Example 1 Preparation of Aqueous Acid Composition

A typical antimicrobial solution can be prepared by first dissolving thesolid citric acid in deionized water, admixing with phosphoric acid andthen adding the required amount of ION or 12N hydrochloric acid. Theamount of the dissolved acids and deionized water may be precalculatedto achieve the following range of concentration of the individual acids:citric, 6-10% (by weight), phosphoric acid, 5-10% (by volume), andhydrochloric acid, 0.1-5% (by volume).

An acid composition according to the invention was prepared using thefollowing recipe.

Container #1: 170 ml of 75-80% concentrated phosphoric acid was added to250 ml of 12N hydrochloric acid (which is approximately 28-32%). Themixture was thoroughly stirred. Ventilation was required as there werefumes from each acid and from the mixture.

Container #2: 0.6 lbs (9.6 oz.) of granular citric acid was thoroughlymixed in 0.8 gallons (102 oz.) of water until dissolved after whichcontainer #1 containing the phosphoric/hydrochloric acid mixture wasadded and thoroughly mixed. The resulting acid composition consisted ofapproximately one gallon. Fumes from the resulting mixture weresubstantially eliminated and the pH was approximately 0.07.

Example 2 Acid Composition as an Antimicrobial Solution

An E. Coli C600 bacterial strain was obtained from a commercial source.This bacterium was grown at 37° C. overnight in 500 ml of Brain-HeartInfusion broth (Difco), previously sterilized in an autoclave (121° C.,15 psi, 15 minutes). After the bacterial culture reached mid log phase,organisms were centrifuged (˜5,000 rpm) in 50 ml centrifuge tubes(Corning). The bacterial pellet was washed twice in 10 mM imidazole, 150mM NaCl (pH 7.2), and once in distilled water before resuspending indistilled water to approximately 1.4×10⁹ colony forming units per ml(cfu/ml).

Three sets of serial 10 fold dilutions ranging from undiluted to 10⁻⁹ ofthe acid composition generated in Example 1 were then made in sterile1.5 ml eppendorf tubes using sterile distilled water. A specific volume(100 μl) of the previously made bacterial suspension was added to 100 μlof each dilution in each of the three sets of serial 10 fold acidcomposition dilutions.

The first set of bacteria and acid composition dilutions were incubatedfor 6 minutes at room temperature. The incubated cells were immediatelycentrifuged at 5,000 rpm for 30 seconds and the supernatant discarded.Each bacterial pellet from each dilution was resuspended 200 μl ofsterile distilled water and placed into separate plastic petri dishes.Sterile molten Brain-Heart Infusion (BHI) agar (˜55° C.) was added toeach petri dish containing the bacteria. Plates were allowed to solidifyon the bench and were inverted and incubated at 37° C. until observablegrowth was evident. Bacterial colonies were counted and recorded ascfu/ml.

The same procedure was followed for the second and third sets of acidcomposition dilutions containing 100 μl aliquots of bacterialsuspension. However, the second set was incubated for one hour and thethird set was incubated for three hours. After washing, cells werewashed with sterile distilled water, plated, and the plates incubated at37° C. for 16-20 hours. The effectiveness of different dilutions of acidcomposition with relation to time, against the E. Coli strain C600 isshown in Table 1.

TABLE 1 Effectiveness of Acid Composition as an Antimicrobial Agent onE. Coli Strain C600 Log Time (minutes) Dilution CFU on Plate Reduction*Bacterial Control 100% Water 5 × 10¹⁰ cfu/ml 0 6 Undiluted 0 ~10 610⁻¹ >5000 (TNTC) 0 6 10⁻² >5000 (TNTC) 0 6 10⁻³ >5000 (TNTC) 0 60Undiluted 0 ~10 60 10⁻¹ 0 ~10 60 10⁻² >5000 (TNTC) 0 60 10⁻³ >5000(TNTC) 0 180 Undiluted 0 ~10 180 10⁻¹ 0 ~10 180 10⁻² 42  ~6.5 18010⁻³ >5000 (TNTC) 0 *Initial bacterial population was 5 × 10¹⁰ cfu/ml.

Effective dilutions of the acid composition were 10⁻¹ and 10⁻² for anyof the three incubation times listed. All undiluted samples of thebacteriocidal agent were effective in reducing the E. Coli bacterialculture by 10 logs. At 10⁻¹ dilution, 6 minutes was insufficient time toeffect the bacterial population of E. Coli. At 60 and 180 minutes, the10⁻¹ dilution reduced the bacterial culture by 10 logs. At 10⁻²dilution, 60 minutes was not effective in bacterial population reductionwhile 180 minutes was effective in reducing the bacterial count to4.2×10³ cfu/ml.

Example 3 Effectiveness of Acid Composition as an Antimicrobial Agent ofB. subtilis

The bacterial strain used in this study was Bacillus subtilis strain#19659 obtained from the American Type Culture Collection (ATCC). Thisbacterium was grown at 28° C. overnight in 500 ml of sterilized complexmedium (BHI broth; Difco). After the bacterial culture reached mid logphase, organisms were centrifuged (˜5,000 rpm) in 50 ml centrifuge tubs(Corning). The bacterial pellet was washed two times in 10 mM imidazole(150 mM NaCl, pH 7.2) and once in distilled water before resuspending indistilled water to approximately 5×10¹⁰ colony forming units per ml(cfu/ml).

Three sets of serial 10 fold dilutions ranging from undiluted to 10⁻⁹ ofthe acid composition of Example 1 were made in sterile 1.5 ml eppindorphtubes using sterile distilled water. A specific volume (100 μl) of thepreviously made bacterial suspension was added to each dilution in eachof the three sets of serial 10 fold acid composition dilutions. Thefirst set of bacteria with acid composition dilutions was incubated for6 minutes at room temperature. Cells were immediately centrifuged at5,000 rpm for 30 seconds and the supernatant was discarded. Eachbacterial pellet from each dilution was resuspended in 200 μl of steriledistilled water and placed into separate plastic petri dishes. Sterilemolten BHI agar (˜55° C.) was added to each petri dish containing thebacteria and allowed to solidify. Solidified plates were inverted andincubated at 28° C. until observable growth was evident. Bacterialcolonies were counted and recorded as cfu/ml.

The same procedure was followed for the second and third sets of acidcomposition dilutions containing 100 μl aliquots of bacterialsuspension. However, the second set was incubated for one hour and thethird set was incubated for three hours. After incubation, cells werewashed with sterile distilled water, poured into plates and incubated at28° C. for 16-20 hours. The effectiveness of different dilutions of acidcomposition with relation to time, against the B. subtilis (ATCC #19659)can be seen in Table 2.

TABLE 2 Effectiveness of Acid Composition as an Antimicrobial Agent ofB. subtilis (ATCC #19659) Acid Composition Log Time (minutes) DilutionCFU on Plate Reduction* Bacterial Control 100% Water 1.4 × 109 cfu/ml 06 Undiluted 0 ~9 6 10⁻¹ 0 0 6 10⁻² 0 0 6 10⁻³ >5000 (TNTC) 0 60Undiluted 0 ~9 60 10⁻¹ 0 ~9 60 10⁻² 0 0 60 10⁻³ >5000 (TNTC) 0 180Undiluted 0 ~9 180 10⁻¹ 0 ~9 180 10⁻² 0 ~9 180 10⁻³ >5000 (TNTC) 0*Initial bacterial population was 1.4 × 10⁹ cfu/ml.

The effective dilutions of the acid composition against B. subtilis were10⁻¹ and 10⁻² for all three of the incubation times listed. Allundiluted samples of the bacteriocidal agent were effective in reducingthe B. subtilis bacterial culture by approximately nine logs. At 10⁻³dilution, none of the times tested were effective in reducing thebacterial population.

Example 4 Further Dilutions of Acid Composition

The bacterial strain used in this study was Bacillus subtilis strain#19659 from American Type Culture Collection (ATCC). This bacterium wasgrown at 28° C. overnight in 500 ml of sterilized complex medium (BHIbroth from Difco). After the bacterial culture reached mid log phase,organisms were centrifuged (˜5,000 rpm) in 50 ml centrifuge tubes(Corning). The bacterial pellet was washed two times in 10 mM imidazole(150 mM NaCl, pH 7.2) and once in distilled water before resuspending indistilled water to approximately 2.8×10⁹ colony forming units per ml(cfu/ml).

One set of dilutions of the acid composition of Example 1 were then madewhich ranged from undiluted, 10⁻¹, 10⁻², and 10⁻³, as well as nine otherdilutions between 10⁻² and 10⁻³. All dilutions were made in sterile 1.5ml eppendorf tubes using sterile distilled water. A specific volume (100μl) of the previously made bacterial suspension was then added to eachacid composition dilution. The bacteria and each dilution of acidcomposition were incubated for 60 minutes at room temperature. The cellswere immediately centrifuged at 5,000 rpm for 30 seconds and thesupernatant was discarded. Each bacterial pellet from each dilution wasresuspended in 200 μl of sterile distilled water and placed intoseparate plastic petri dishes. Sterile molten BHI agar (˜55° C.) wasadded to each petri dish containing the bacteria. Plates were allowed tosolidify, inverted, and incubated at 28° C. until observable growth wasevident. Bacterial colonies were counted and recorded as cfu/ml. Theeffectiveness of different dilutions of acid composition with relationto time, against the B. subtilis (ATCC #19659) can be seen in Table 3.

TABLE 3 Effectiveness of Acid Composition as an Antimicrobial Agent onB. subtilis (ATCC #19659) Acid Composition Log Time (minutes) DilutionCFU on Plate Reduction* Bacterial Control 100% Water 2.8 × 10⁹ cfu/ml 060 Undiluted 0 ~9 60 10⁻¹   0 ~9 60 10⁻²   0 ~9 60 10^(−2.1) 0 ~9 6010^(−2.2) 0 ~9 60 10^(−2.3) 0 ~9 60 10^(−2.4) 0 ~9 60 10^(−2.5) 0 ~9 6010^(−2.6) 0 ~9 60 10^(−2.7) 2.1 × 10¹ ~8 60 10^(−2.8) 4.8 × 10⁴ ~6 6010^(−2.9) 6.3 × 10⁶ ~3 60 10⁻³   >5000 (TNTC) 0 *Initial bacterialpopulation was 2.8 × 10¹⁰ cfu/ml.

Effective dilutions of the acid composition against B. subtilis werefrom 10⁻¹ to 10^(−2.6) for the 60 minute incubation time. Once again theundiluted sample of the bacteriocidal agent was effective in reducingthe B. subtilis bacterial culture by approximately nine logs.

Example 5 Effectiveness of Acid Composition as an Antimicrobial AgentAgainst E. Coli

The acid composition of Example 1 was used for the following testing.Testing was performed using nalgene tubing ( 1/16 inch in diameter). Aculture of Escherichia coli was passed through three 3-inch sections oftubing and allowed to incubate for 15 minutes at room temperature. Onesection of tubing was rinsed with one ml of sterile water and theportion of the water remaining in the tube was allowed to incubate for15 minutes at room temperature. This was repeated using acid compositionsolution and a 10% solution for the remaining tubing sections. Eachsection was then rinsed with 0.5 ml of sterile water and the rinse wasassayed for bacteria by plating.

TABLE 4 Effectiveness of Acid Composition as an Antimicrobial Agentagainst E. Coli cfu/ml* (+/−SD) Tubing Treatment 455 +/− 120 water 2 +/−2 10% Acid Composition 0 100% Acid Composition *cfu/ml = colony-formingunits per milliliter.

Example 6 Effectiveness of the Acid Composition as an AntimicrobialAgent Against S. cerevisiae

To determine the efficacy of the acid composition against fungalpathogens, the acid composition of Example 1 was used as an antifungalagainst Saccharomyces cerevisiae. Fungal cells were grown and mixed witheither water or various concentrations of acid composition with water(50/50, vol./vol.). These were incubated for 15 minutes at roomtemperature followed by plating to determine viability. Percentsurvival, shown below, represents plate counts relative to the watercontrol.

TABLE 5 Effectiveness of Acid Composition as an Antimicrobial Agentagainst S. cerevisiae % Survival (+/−SEM) Acid Composition Concentration102 +/− 22  0% (100% water) 6 +/− 4 10% Acid Composition 0 100% AcidComposition

Example 7 Preparation of a BC for Testing Efficacy as DecontaminationAgent

A base compound (BC) according to the invention was prepared by mixing200 ml hydrochloric acid (12N), 170 ml phosphoric acid and 125 gramscitric acid generally as described in Example 1. BC was supplementedwith additives and utilized in the reaction assays as described below.The test compounds produced were made by first forming BC, and thenusing BC for the direct addition of supplements. Unless otherwisestated, all additions, mixing, etc. were performed at room temperature.Liquids added as supplements at a given percent concentration refers tothe volume to volume ratios of supplement to BC. For solids, the amountwas weighed out, added to an aliquot of BC and allowed to dissolve, thenadded to the BC to achieve the appropriate final volume.

Example 8 Inhibition of CW-Mime Agents Materials and Methods

Chemical Warfare (CW) agents and CW-like or mime agents include a numberof classes of compounds utilizing different mechanisms of action. Onesuch class, nerve agents, such as diisopropyl fluorophosphate (DFP),inhibits acetylcholinesterase. DFP also inhibits the activity of serineproteases like trypsin. Paraoxan, a DFP-like molecule, (diethylp-nitrophenyl phosphate) has a chemistry similar to DFP. Like DFP,paraoxan inhibits trypsin. Because of the similarity, paraoxan was used,as described below, as a DFP mime or model to study the efficacy of BCand modified forms of BC to inactivate the enzyme-inhibiting ability ofthis agent. In the experiments which follow, trypsin coupled to agarosebeads is used as an assay for paraoxan, using the standard calorimetricassay for trypsin, BAEE (N-benzoyl-L-arginine ethyl ester). In additionto testing BC, reactive substances were also introduced into BC to testefficacy in inhibiting paraoxan.

By identifying agents that can prevent paraoxan from inactivating aserine protease, decontamination compounds can be identified and furtherdeveloped. The relative safety of paraoxan, the ease of assay for aserine protease, and the large margin of safety of previouslymanufactured test compounds make paraoxan particularly useful forscreening modified test compounds.

The ability of paraoxan to inhibit the serine protease trypsin wasassessed by placing an aliquot of paraoxan into distilled water (at aratio of 1:100, paraoxan:water), followed by mechanical mixing of thesolution. This stock of paraoxan was then used for assays in which 10 μlof this paraoxan stock was mixed with 10 μl of one of the test compoundsof the present invention (see below) and incubated for various timeperiods (5, 15, and 60 minutes). The reactions were stopped by theaddition of 20 μl of 1 M imidazole, 100 mM NaCl, pH 7.8.

Paraoxan solutions were then incubated with the serine protease,trypsin, and the activity of the trypsin was monitored as describedbelow. A trypsin stock solution was freshly prepared for each experimentby weighing out 10 mg, and resuspending this into 1 ml of ice colddistilled water until use (within 15-30 minutes). Trypsin activity wasassessed by diluting the trypsin stock 100-fold in 10 mM imidazole, 100mM NaCl, pH 7.8, and placing 50 μl of this solution into ELISA wells(three rows per individual test experiment). Paraoxan solutions preparedas described above were added to the trypsin. This was allowed toincubate for 30 minutes at room temperature. A 2-fold serial dilution ofthese mixtures were then performed using 10 mM imidazole, 100 mM NaCl,pH 7.8 for each incubation mixture of trypsin and paraoxan/testcompound. A negative control was also prepared by omitting the additionof the paraoxan, and adding distilled water alone.

Azocoll (an azo-dye impregnated collagen) was used to detect serineprotease activity and was the basis for screening the various testcompounds. A sample of azocoll was diluted into 10 mM imidazole, 150 mMNaCl, pH 7.8 (10 mg/ml) and incubated at room temperature for 15 to 30minutes before use. For distribution of the azocoll into ELISA platetest wells, 200 μl pipette tips were modified by cutting 2 to 3 mm offof the end of each tip which permitted the azocoll particles to beeasily moved freely into and out of the pipettor. To insure that similaramounts of azocoll were distributed to each test well, the azocollsuspension was mixed prior to withdrawing the aliquots with the modifiedpipette tips, and the pipettor was flushed three times with thesuspension, using the third uptake stroke to obtain the azocoll for eachwell. This volume (100 μl) was placed into each test well containing theserially-diluted trypsin and paraoxan/test compound mixtures prepared asdescribed above.

Enzymatic activity was determined by visual inspection of the azocollparticles placed into the ELISA test wells after at least a 30 minuteincubation period at room temperature. Maximal trypsin activity wasdetermined by the examination of the negative controls, in which onlytrypsin and water were present. The development of soluble coloredproduct indicated that protease activity had occurred and the maximaldilution of trypsin that could produce this color was taken as 100%trypsin activity. For each individual experiment, comparisons ofactivity were made relative to internal controls prepared for thatexperiment. Any diminution of the dilution of trypsin which could stillproduce a soluble, colored product would indicate that the trypsinactivity had been inhibited. The level of maximum trypsin inhibition wastaken as the paraoxan-water control described above. As was the case forthe control for maximal trypsin activity, this control was performed foreach individual trypsin stock solution preparation for each experimentperformed. In addition, a control for each test compound alone, in theabsence of paraoxan, was performed to insure that any inhibition ofactivity was due to the action of paraoxan, and not the test compounditself.

Results are expressed as integral numbers which represent the increasein the well number (or increase in dilution of trypsin) that proteaseactivity could be detected. Results are given as whole integers, whereinthe integer represents x in the expression 2_(x). An x value of 0indicates no change, an x value of 1 indicates that the trypsin could bediluted by half and activity was detected, an x value of 2 indicatesthat the trypsin could be diluted by 4 and activity was visible, an xvalue of 3 diluted by 8, etc. The integer represents the mean of eachset of results rounded to the nearest whole integer.

As described below, test compounds were added to solutions to determineif there was any effect on the extent of paraoxan-induced trypsininhibition. These effects were detected by the development of solublecolored product from the azocoll at higher serial dilutions of thetrypsin solutions relative to the paraoxan-water and trypsin incubation.For example, compositions of the present invention include derivativesof BC which contain oxime reagents. Another test compound containsamine. These derivative compositions based upon BC may be useful inoptimizing a decontaminating compound for the destruction of CW agentsand mimes. The results which follow indicate that BC, alone and incombination with other additives, does in fact effect the ability ofparaoxan to inactivate trypsin.

Example 9 Effectiveness of Permanganate-Containing BC Solution inDeactivating Chemical Warfare Agents

Permanganate-containing test compounds were produced by the addition of0.1, 1 and 10 mM potassium permanganate to BC. These compounds weredesignated as TC02157-0.1, TC02157-1, and TC02157-10, respectively.Controls compounds or sham compounds consisting of these samepermanganate concentrations in water were also assessed for activity andare designated as SC02157-0.1, -1, -10, respectively. After incubationwith the paraoxan, each solution was supplemented with 1 M imidazole,100 mM NaCl (pH 7.8) to bring the pH to 7.8. The solutions were thenadded to the freshly prepared trypsin solutions and allowed to incubate.The trypsin solutions containing the paraoxan and test compound mixtureswere then serially diluted, followed by the addition of the trypsinactivity indicator, azocoll. After 30 to 60 minutes, the plate wellswere inspected for trypsin activity, where a soluble colored productindicated that trypsin activity could be detected through the release ofdye from the insoluble azocoll reagent. Each experiment represents theaverage, rounded to the nearest whole integer, of two sets of ELISAplates with 6 dilution series for each test compound and sham. The datain Table 6 represent the fold increase in trypsin activity due to thetest compound over the trypsin activity treated with paraoxan alone/foldincrease in trypsin activity due to the sham compound over the trypsinactivity treated with paraoxan alone (test compound without permanganatewas 1).

TABLE 6 Inhibition of the Paraoxan-Induced Inactivation of Trypsin byTest Compounds TC02157-0.1/SC-0.1 TC02157-1/SC-1 TC02157-10/SC-1 Expt 12/0 2/0 5/1 Expt 2 1/0 2/0 4/1 Expt 3 1/0 1/0 3/1

Indications from the above experiments (results presented as the meanincrease for six separate experiments) suggested that the compoundssupplemented with permanganate may serve to increase the ability of testcompounds to inactivate paraoxan, and might serve as the basis forfuture tests of the inactivation of DFP directly. The ability of thesham compound SC-10 to inhibit activity was not expected, however thecombination of BC with the permanganate increased the ability of themixture to inhibit paraoxan activity with over a two-fold increase.

It was subsequently determined that further increases in permanganateions, to values of 50, 100, and 250 mM concentrations, did not increasethe ability of the test compounds to inhibit paraoxan activity (Table7). The data in Table 7 represents the fold increase in trypsin activitydue to the test compound over the trypsin activity treated with paraoxanalone/fold increase in trypsin activity due to the sham compound overthe trypsin activity treated with paraoxan alone.

TABLE 7 Effect of Increasing Permanganate on Test CompoundsTC02157-50/SC-50 TC02157-100/SC-100 TC02157-200/SC-200 5/1 5/2 5/2

These results suggest that a range of no more than 10 mM permanganateshould is most useful. Studies on the effect of time and temperature onthe activity of the test compounds supplemented with permanganate werealso performed. Experiments were designed to perform the paraoxan testinactivation assays at 4° C. in the test compounds supplemented withpermanganate. No significant differences were found in the ability toinactivate paraoxan activity at the lower temperatures (not shown).

A series of time course experiments were decided upon due to the changein color of test compound solutions over time. For this series of timecourse experiments, test compounds were prepared supplemented withpotassium permanganate, and a sequence of experiments were performedover the time course of one month. At days 0, 1, 3, 7, 14, 21, and 28paraoxan inactivation assays were run at room temperature. Test compoundwas stored in a polypropylene bottle at room temperature during thistime period for use in the assays. For any given day, an aliquot of thestored test compound (supplemented with 10 mM permanganate as described)was removed, and two separate sets of test assays were performed on twotrypsin test solutions performed in triplicate as described in methods.The ability of this stored test compound to inhibit paraoxan activity ispresented below, presented as the mean of the activity.

TABLE 8 Time Course of Activity of Permanganate-Supplemented TestCompounds TC02157-0.1/SC-0.1 TC02157-1/SC-1 TC02157-10/SC-1 Day 0 3/03/0 6/1 Day 3 3/0 2/0 4/1 Day 7 2/0 2/0 3/0 Day 14 1/0 1/0 1/0 Day 211/0 0/0 −1/0  Day 28 1/0 0/0 −1/−1

The data shown in Table 8 represent the fold increase in trypsinactivity over the trypsin inhibition by paraoxan alone on a given day,as described in methods. The decrease in the paraoxan-inhibitingactivity of the test compound seen in these experiments indicate thatpermanganate ions may degrade the ability of the test compound toinhibit paraoxan activity. Similar experiments were performed using testcompounds stored at 4° C. and at −20° C. in an attempt to delay orinhibit the reaction. No significant differences were seen in theseexperiments (not shown). Permanganate may be detrimental to the testcompound activity under these conditions. Compounds based on supplementswith permanganate may require a two-step procedure with a rapid mixprior to use.

Example 10 Efficacy of BC Mixed with Other Agents

The above results show that the test compounds supplemented withpermanganate may serve as the basis for inactivation of DFP directly,however, the functional lifetime of the effectiveness of the compoundsmay have been compromised, as after 7 days a significant decrease ineffectiveness was noted. The following experiments were performed inwhich BC was supplemented with other agents that have previously beenimplicated in extending the shelf-life of test compounds (not shown).Specifically, ZnCl₂ (10 μM), MnCl₂ (10 μM), and diethanolamine (5 μM, 50μM, and 100 μM) were utilized as additives to the test compoundTC02157-0.1 and the sham SC-0.1. These additions to the test compoundwere performed, and the resultant solutions were assayed for longevityas performed above. For the following results, the data are presented interms of the relative difference (if positive) between the highestdilution of trypsin activity detected for the test compound minus thatfound for the sham compound. All ions were used at a concentration of 10mM added in the chloride form. Diethanolamine concentrations of 5, 50,and 500 μM are presented as D5, D50, and D100, respectively, in Table 9below.

TABLE 9 Effect of Zn, Mn, and Diethanolamine on the Loss of Activity ofPermanganate-Supplemented Test Compounds TC02157-0.1 +Zn +Mn +D5 +D50+D100 Day 0 3 3 3 3 3 Day 3 3 2 3 3 3 Day 7 3 2 2 2 2 Day 14 2 1 1 1 2Day 21 1 1 1 1 2 Day 28 1 0 1 1 1

The data shown in Table 9 represent the fold increase in trypsinactivity over the trypsin inhibition by paraoxan alone on a given day,as described above. The results showed that both the ZnCl₂ and MnCl₂ didnot significantly alter the loss of activity after 7 days, however,there was a slight increase in overall activity, possibly due to thedivalent cations and/or their interaction with the permanganate. Nodifference was seen using any of the diethanolamine supplementsdescribed above. Similar results were seen when the experiment wasrepeated after a 14 day incubation. There was a noticeable color changein the solutions supplemented with diethanolamine after this period oftime and a loss of activity. Incubation times of over 21 days, however,indicated that the inhibition of activity might be delayed bydiethanolamine or Zn ions in combination with thepermanganate-supplemented compound.

These studies indicate that the increase in activity attributed to thepermanganate might result in a decrease in efficacy of compoundsaccording to the invention within a short period of time. Concurrentwork with other test compounds containing permanganate relative tocontrol test compounds without permanganate had higher paraoxaninhibiting activities and did not lose this activity over similar timeperiods. In view of this, other supplements to BC were examined. Othersupplements that were found to either show no enhancement ofparaoxan-inhibiting ability or an incompatibility with the test assaysystem include mercaptoethanol, iodoacetamide, iodoacetic acid andthiosulfate ions.

Further experiments were carried out to test a BC composition containing1% tert-butanol, 1% hydrogen peroxide, 100 μM ZnCl₂ and 10 mMhydroxylamine. This compound reverses the inhibitory effects of paraoxanon trypsin activity. BC composed of hydrochloric acid, phosphoric acidand citrate (as described in Example 1) was prepared and supplementedwith various concentrations of zinc ions in the form of zinc chloride(0.1, 1, 10, 100 and 200 mM).

TABLE 10 Inhibition of Paraoxan-Induced Inactivation of Trypsin byZn-supplemented BCs as a Function of Time after Production of TestCompounds Zinc Supplement (mM) 0.1 1 10 100 200 Activity, Day 0 2 2 3 10 Activity, Day 7 2 2 3 1 0 Activity, Day 21 2 2 4 1 0 Activity, Day 282 2 3 1 0

Based on this study, it was determined that at very high concentrationsof zinc, some direct inhibition of trypsin activity was occurring inthis assay system during exposure of the trypsin to the test compounditself, as the controls containing no paraoxan were similarly inhibited,resulting in no differences being detected. The activity of thesupplement at 10 mM, however, indicates that some augmentation can bedetected. No decrease in activity was seen over the course of 28 days.Further experiments indicate that no significant change in activityoccurred over a period of three months (not shown).

Other cations, such as Ca++, Cu++, Fe+++, Mn++, and Co++ were assessedfor their ability to augment the paraoxan-inhibiting activity of theBCs. For the ions Ca and Mn, the assay system controls were altered suchthat these supplements could not be easily assessed due to some directinhibition of the trypsin in the absence of paraoxan. Limitedaugmentation of activity was detected using Fe, Cu and Co; however, theslim increase declined rapidly upon storage.

BC was prepared and a series of test compounds containing variousamounts of butanol (0.1, 0.5, 1, 5, 10, 20, and 30%). Thesebutanol-supplemented compounds were then used in paraoxan inhibitionassays as described previously. For the following results, the integersexpressed are the changes in trypsin dilution with delectable proteaseactivity relative to the unsupplemented BC alone. For these results,each positive integer represents a “1” will increase in trypsin activity(i.e. a two-fold increase). Any diminution in the dilution isrepresented by a similar, negative integer. A “0” indicates no changerelative to the unsupplemented compound. Any positive integer wouldindicate that the ability of paraoxan to inhibit protease activity hasbeen limited by the addition of the supplement. No detectable inhibitionof trypsin activity was detected induced by the butanol in the absenceof paraoxan (not shown).

TABLE 11 Effect of Butanol on the Inactivation of Paraoxan-MediatedEffects by Test Compounds Butanol (%) 0.1 0.5 1 5 10 20 33 Activity 0 00 1 2 4 5

The ability of butanol to enhance the paraoxan-inhibiting activity ofthe BC at 20 to 33% concentration was seen over a period of one month(not shown). A shorter chain alcohol, propanol, was then tested in asimilar set of experiments. An increase in activity (2-fold) was seen atthe 33% concentration, with negligible enhancement of BC activity.

No change was noted with time for propanol. No activity enhancement wasseen using the shorter chain alcohols ethanol and methanol (not shown).It should be noted that for butanol, the mixture can separate uponstorage. The test compounds supplemented with butanol were premixed byshaking prior to distribution for testing.

Hydrogen peroxide supplemented BCs were prepared at peroxideconcentrations of 0.1, 0.5, 1, 2, and 5%. As presented for the butanoldata above, the integers represent the increase in dilution whichpermitted detection of protease activity.

TABLE 12 Effect of Hydrogen Peroxide Addition on the Ability of TestCompounds to Deactivate Paraoxan-Mediated Trypsin Inhibition HydrogenPeroxide (%) 0.1 0.5 1 2 5 Activity 0 0 1 1 1

A kinetic study on the lifetime of any enhancement detected wasperformed for hydrogen peroxide-supplemented compounds. It was noticedthat after 1 day (and later determined that within 2 to 4 hours), nodelectable change was seen in that no enhancement occurred after 2 to 4hours of incubation prior to performing the assay.

Hydroxylamine hydrochloride was used as a supplement to the BC inconcentrations of 1, 2, 5, 10, and 20% (wt./vol.). The effect ofhydroxylamine is expressed as the change seen relative to BC notcontaining any supplement.

TABLE 13 Inactivation of Paraoxan-Mediated Inhibition of Trypsin byHydroxylamine Supplemented BCs Hydroxylamine (1%) 1 2 5 10 20 Activity,Day 0 0 0 1 2 1 Activity, Day 45 0 0 2 1 1

No significant change in this activity has been detected for compoundsstored at room temperature for up to 60 days (not shown). The oximes 2,3butanedione monoxime (BDM) and 2-pyridine aldoxime methchloride (PAM)were also tested as supplements to BC. No inhibition of trypsin activitywas seen caused by either of these oxime supplements alone in theabsence of paraoxan. For these investigations, the integers representthe differences in dilutions of trypsin that showed protease activity,where positive integers are equivalent to an increase in the dilution oftrypsin that still permits the detection of protease activity relativeto unsupplemented BC. As in the immediately preceding cases, anypositive activity integer would indicate that the ability of paraoxan toinhibit protease activity has been dampened by the addition of thesupplement. BC supplemented with oxime reagents were tested atconcentrations of 0.01%, 0.1%, 0.3%, 0.5%, 1%, 2%, and 5% (weight tovolume).

TABLE 14 Effect of Oxime (PAM and BAM) Supplements on the Ability ofTest Compounds to Inactivate Paraoxan-Mediated Reactions PAM (1%) 0.010.1 0.3 0.5 1 2 5 Activity 0 0 0 1 2 2 2 BDM (%) 0.01 0.1 0.3 0.5 1 2 5Activity 0 0 0 0 1 1 0

In the case of PAM, the ability to inhibit Paraoxan was optimal at a 1%concentration. Similar results were obtained for BDM, however the PAMwas more effective at all concentrations tested relative to BDM. The 1%concentrations of both reagents in BC were then supplemented with zincchloride. No significant enhancement was noted except for the use of 10mM zinc chloride in conjunction with PAM (not shown). Some increase inactivity could be detected by the addition of the above supplements withPAM showing the most increase.

A new series of compounds were prepared that combined some of thesupplements tested above in BC, using combinations of the supplementsshown to be most effective in enhancing the “decon” activity of the testcompounds in inhibiting the paraoxan-induced inhibition of trypsin. As afirst step, zinc ions at 10 mM concentration were added to testcompounds prepared supplemented with hydroxylamine at a 10%concentration. Results in the table below represent the difference inactivity of this double-supplemented BC relative to the BC containinghydroxylamine alone. A similar set of experiments was performed usingzinc (10 mM) added to butanol-supplemented (30%) BC. A time course ofassessment of activity was performed for the solutions stored at roomtemperature. The data indicate that zinc may enhance the activity of thehydroxylamine while either not affecting or even limiting thebutanol-supplemented BC. No significant differences in this were seenover the time course of one month.

TABLE 15 Effect of Zn (10 mM) Addition on the Ability Supplemented TestCompounds to inhibit Paraoxan-Mediated Effects Zn + Hydroxylamine Zn +Butanol Activity, Day 0 1 0 Activity, Day 1 1 −1 Activity, Day 7 0 0Activity, Day 014 1 0 Activity, Day 21 1 −1 Activity, Day 28 0 0

As can be seen in the foregoing example, butanol, hydroxylamine, zincchloride and the oxime 2-pyridine aldoxime methchloride can enhanceinactivation of the ability of compositions according to the inventionto deactivate potentially toxic molecules. The effect of thesesupplements does not decay over time.

Example 11 Use of BC to Inactivate Other Agents

Solutions according to the invention have been used to kill virus andbacteria. BC at 20, and 5% diluted with distilled water reduced type 1polio virus concentration by at least 10⁵. Bacterial assays were alsopositive. A 15% strength solution of BC in water for 10 minutes resultedin less than 1% survival for E. Coli LP 1395 cells. For Enterobacteraerogenes, the survival was less than 0.5% under similar conditions. A1% solution of BC inactivates botulinum toxin more than 99.99% within 1minute.

Other embodiments and uses of the invention will be apparent to thoseskilled in the art from consideration of the specification and practiceof the invention disclosed herein. All references cited herein, forwhatever reason, are specifically incorporated herein by referenceincluding U.S. patent application, entitled “Hypertonic AqueousSolutions of Polybasic Acid Salts” filed contemporaneously herewith. Thespecification and examples should be considered exemplary only with thetrue scope and spirit of the invention indicated by the followingclaims.

1. An acidic solution for inhibiting microbial growth comprising anaqueous acidic core composition, said acidic solution comprising fromabout 50 to about 100 percent of said acidic core composition, saidacidic core composition consisting of acids safe for use in food anddrink products and food- and drink-associated products, said acid corecomposition prepared by the steps of: admixing from about 1 to about 5volume percent of a first acid, said first acid being an inorganic acidthat dissociates nearly to completion in water, with about 5 to about 10volume percent of a second acid, said second acid being an inorganicacid less strong than said first inorganic acid, said second acid havinga dissociation constant of less than about 10⁻¹, to produce a firstacidic composition; and admixing from about 6 to about 10 weight percentof a hydroxy acid, having at least twice the chelating capability ofsaid first and second acids, with water to produce a second acidiccomposition; and admixing said first acidic composition with said secondacidic composition to produce said acid core composition having a pH ofless than one and wherein said acidic core composition will not reactwith human tissue.
 2. The acidic solution of claim 1 wherein the firstacid is hydrochloric acid.
 3. The acidic solution of claim 1 wherein thesecond acid is phosphoric acid.
 4. The acidic solution of claim 1wherein the hydroxy acid is an organic acid.
 5. The acidic solution ofclaim 1 wherein the hydroxy acid is a weak acid relative to said firstand second acids, said hydroxy acid having a dissociation constant offrom about 10⁻¹ to 10⁻⁵.
 6. The acidic solution of claim 1 wherein thehydroxy acid serves as a conjugate base to said first inorganic acid. 7.The acidic solution of claim 1 wherein the first acid of said acidiccore composition is safe for use in food and drink products and in food-and drink-associated products.
 8. The acidic solution of claim 1 whereinthe second acid of said acidic core composition is safe for use in foodand drink products and in food- and drink-associated products.
 9. Theacidic solution of claim 1 wherein the hydroxy acid is a hydroxycarboxylic acid.
 10. The acidic solution of claim 9 wherein the hydroxycarboxylic acid is selected from the group consisting of ascorbic,citric, lactic, malic and tartaric acids.
 11. The acidic solution ofclaim 1 wherein the hydroxy acid is a tricarboxylic acid.
 12. The acidicsolution of claim 1 wherein the hydroxy acid consists of at least threecarbon atoms.
 13. The acidic solution of claim 1 wherein the hydroxyacid is an acid safe for use in food and drink products and in food- anddrink-associated products.
 14. The acidic solution of claim 1 whereinthe hydroxy acid is citric acid.
 15. The acidic solution of claim 1wherein the solution is safe for use in ingestible products.
 16. Theacidic solution of claim 1 wherein the solution is safe for use onsurfaces that contact ingestible products.
 17. The acidic solution ofclaim 1 wherein the pH of said solution is less than one.
 18. The acidicsolution of claim 1 wherein the solution is nonreactive with human skin.19. The acidic solution of claim 1 wherein the acidic core compositionis substantially non-corrosive to metals.
 20. The acidic solution ofclaim 1 wherein the solution is substantially non-corrosive to metals.21. A pharmaceutical compound comprising a three acid composition, saidthree acid composition comprising: a first acid, said first acid beingan inorganic acid that dissociates nearly to completion in water; asecond acid, said second acid being an inorganic acid less strong thansaid first inorganic acid and having a dissociation constant of lessthan about 10⁻¹; and a third acid, said third acid being an organic acidweaker than said first and second acids, said third acid having adissociation constant of from about 10⁻¹ to 10⁻⁵ and having chelatingcapability of at least twice said first and second inorganic acids; anda pharmaceutical agent.
 22. The pharmaceutical compound of claim 21wherein the first, second and third acids are GRAS acids.
 23. Thepharmaceutical compound of claim 21 wherein the pharmaceutical agent isselected from the group consisting of a gel, a cream, a surfactant, anemollient, a lotion, and a liquid.
 24. The pharmaceutical compound ofclaim 21 wherein the compound is safe for human ingestion.
 25. Acomposition for processing food comprising: a first GRAS acid, saidfirst GRAS acid being an inorganic acid that dissociates nearly tocompletion in water; a second GRAS acid, said second GRAS acid being aninorganic acid less strong than said first GRAS acid and having adissociation constant of less than about 10⁻¹; and a third GRAS acid,said third GRAS acid being an organic hydroxy acid weaker than saidfirst and second GRAS acids, said third GRAS acid having a dissociationconstant of from about 10⁻¹ to 10⁻⁵, and having chelating capability ofat least twice said first and second GRAS acids.
 26. The composition ofclaim 25 wherein the first GRAS acid is hydrochloric acid, the secondGRAS acid is phosphoric acid and the third GRAS acid is citric acid. 27.A method of preserving food comprising the step of adding a three acidpreservative composition to a food substance, said three acidpreservative composition comprising: a first GRAS acid, said first GRASacid being an inorganic acid that dissociates nearly to completion inwater; a second GRAS acid, said second GRAS acid being an inorganic acidless strong than said first GRAS inorganic acid and having adissociation constant of less than about 10⁻¹; and a third GRAS acid,said third GRAS acid being an organic acid weaker than said first andsecond GRAS acids, said third GRAS acid having a dissociation constantof from about 10⁻¹ to 10⁻⁵, and having chelating capability of at leasttwice said first and second GRAS acids.
 28. The method of claim 27wherein the first GRAS acid is hydrochloric acid, the second GRAS acidis phosphoric acid and the third GRAS acid is citric acid.
 29. A methodfor decontaminating surfaces comprising the step of contacting saidsurface with a decontaminant comprising a three acid composition, saidthree acid composition comprising: a first GRAS acid, said first GRASacid being an inorganic acid that dissociates nearly to completion inwater; a second GRAS acid, said second GRAS acid being an inorganic acidless strong than said first GRAS inorganic acid and having adissociation constant of less than about 10⁻¹; and a third GRAS acid,said third GRAS acid being an organic acid weaker than said first andsecond GRAS acids, said third GRAS acid having a dissociation constantof from about 10⁻¹ to 10⁻⁵, and having chelating capability of at leasttwice said first and second GRAS acids.
 30. The method of claim 29wherein the surface is decontaminated from one or more contaminantsselected from the group consisting of a bacteria, a virus, a fungus, anaflatoxin, a biological toxin, an exotoxin, an endotoxin, a poison, aphytotoxin, an insect venom, an animal venom, a mycotoxin, aninsecticide, a pesticide, a mustard agent, a nerve agent, a blisteragent, a cholinesterase and a cholinesterase inhibitor.
 31. The methodof claim 29 wherein the surface is a surface which comes into contactwith products used for human consumption.
 32. The method of claim 29wherein the surface is human tissue.
 33. The method of claim 29 whereinthe surface comes into contact with human tissue.
 34. the method ofclaim 29 wherein the three acid composition is contained within a poroussubstance.
 35. The method of claim 29 wherein the three acid compositionis contained within a sponge.
 36. The method of claim 29 wherein thethree acid composition is contained within a towelette.
 37. The methodof claim 29 wherein the three acid composition further comprises anagent selected from the group consisting of a foam, a surfactant, anaerosol, a thickening agent, and a gel.
 38. A method for inhibitingmicrobial growth on a surface comprising contacting said surface with acompound, said compound comprising a three acid composition, said threeacid composition comprising a first acid, said first acid being aninorganic acid that dissociates nearly to completion in water; a secondacid, said second acid being an inorganic acid less strong than saidfirst inorganic acid and having a dissociation constant of less thanabout 10⁻¹; and a third acid, said third acid being an organic acidweaker than said first and second acids, said third acid having adissociation constant of from about 10⁻¹ to 10⁻⁵, and having chelatingcapability of at least twice said first and second acids.
 39. The methodof claim 38 wherein the surface is human tissue.
 40. The method of claim38 wherein the surface is a human eye.
 41. The method of claim 38wherein the compound is contained within a sponge.
 42. The method ofclaim 38 wherein the compound is contained within a towelette.
 43. Themethod of claim 38 wherein the compound is safe for human ingestion.